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We disclose a mediated electrochemical [2+2+2] annulation of alkynes with nitriles, forming substituted pyridines in a single step from low‐cost, readily available starting materials. The combination of electrochemistry and a triarylamine redox mediator obviates the requirements of transition metals and additional oxidants. Besides the formation of diarylpyridine moieties via the homocoupling of two identical alkynes, the heterocoupling of two different alkynes depending on their electronic nature is possible, highlighting the unprecedented control of chemoselectivity in this catalytic [2+2+2] process. Mechanistic investigations like cyclic voltammetry and crossover experiments combined with DFT calculations indicate the initial oxidation of an alkyne as the key step leading to the formation of a vinyl radical cation intermediate. The utilization of continuous flow technology proved instrumental for an efficient process scale‐up. The utility of the products is exemplified by the synthesis of π‐extended molecules, being relevant for material or drug synthesis. [ABSTRACT FROM AUTHOR]

Our study unveils a pioneering methodology that effectively distributes Pd species within a zeolitic imidazolate framework‐8 (ZIF‐8). We demonstrate that Pd can be encapsulated within ZIF‐8 as atomically dispersed Pd species that function as an excited‐state transition metal catalyst for promoting carbon–carbon (C−C) cross‐couplings at room temperature using visible light as the driving force. Furthermore, the same material can be reduced at 250 °C, forming Pd metal nanoparticles encapsulated in ZIF‐8. This catalyst shows high rates and selectivity for carbon dioxide hydrogenation to methanol under industrially relevant conditions (250 °C, 50 bar): 7.46 molmethanol molmetal−1 h−1 and >99 %. Our results demonstrate the correlations of the catalyst structure with the performances at experimental and theoretical levels. [ABSTRACT FROM AUTHOR]

Herein, we disclose the first report on gold‐catalyzed C(sp2)‐CN cross‐coupling reaction by employing a ligand‐enabled Au(I)/Au(III) redox catalysis. This transformation utilizes acetone cyanohydrin as a nucleophilic cyanide source to convert simple aryl and alkenyl iodides into the corresponding nitriles. Combined experimental and computational studies highlighted the crucial role of cationic silver salts in activating the stable (P,N)‐AuCN complex towards the oxidative addition of aryl iodides to subsequently generate key aryl‐Au(III) cyanide complexes. [ABSTRACT FROM AUTHOR]

Comprehensive Summary The EDA complex‐mediated reactions involving oxime esters have been few studied. Herein, an EDA complex formed by thiophenolate anion and oxime ester is reported for photoinduced divergent synthesis of thioethers, depending on different types of oxime esters. Operational simplicity, mild reaction conditions, and flexible options of leaving group demonstrate the generality and synthetic utility of this approach. Such an approach can also enable an interesting thiol‐catalysis for the synthesis of phenanthridines. [ABSTRACT FROM AUTHOR]

Transition metal‐catalyzed cross‐coupling reactions have become a powerful and widely used synthetic approach for the construction of both carbon‐carbon and carbon‐heteroatom bonds. These reactions have revolutionized synthetic chemistry by enabling the efficient formation of complex molecular architectures. Among the various methods available, the bimolecular homolytic substitution (SH2) reaction has emerged as an attractive and versatile method for the formation of C(sp3)−C(sp3) and C(sp3)‐heteroatom bonds. In recent years, significant progress has been made in the development of radical SH2 reactions, particularly those involving different transition metal complexes such as cobalt, nickel, and iron. These advancements have expanded the scope of SH2 reactions, allowing for greater diversity in substrate compatibility and reaction conditions. In this review, we aim to highlight the latest breakthroughs and mechanistic insights into radical SH2 reactions, focusing on the role of transition metal catalysts in facilitating these transformations. We will discuss the various types of transition metal complexes that have been employed, the mechanistic pathways involved, and the potential applications of these reactions in the synthesis of complex organic molecules. [ABSTRACT FROM AUTHOR]

Over the years, polynuclear cyclic or torus complexes have attracted increasing interest due to their unique metal topologies and properties. However, the isolation of polynuclear cyclic organometallic complexes is extremely challenging due to their inherent reactivity, which stems from the labile and reactive metal‐carbon bonds. In this study, the pyrazine ligand undergoes a radical‐radical cross‐coupling reaction leading to the formation of a decanuclear [(Cp*)20Dy10(L1)10] ⋅ 12(C7H8) (1; where L1 = anion of 2‐prop‐2‐enyl‐2H‐pyrazine; Cp* = pentamethylcyclopentadienyl) complex, where all DyIII metal centres are bridged by the anionic L1 ligand. Amongst the family of polynuclear Ln organometallic complexes bearing CpR2Lnx units (CpR = substituted cyclopentadienyl), 1 features the highest nuclearity obtained to date. In‐depth computational studies were conducted to elucidate the proposed reaction mechanism and formation of L1, while probing of the magnetic properties of 1, revealed slow magnetic relaxation upon application of a static dc field. [ABSTRACT FROM AUTHOR]

Comprehensive Summary The EDA complex‐mediated reactions involving oxime esters have been few studied. Herein, an EDA complex formed by thiophenolate anion and oxime ester is reported for photoinduced divergent synthesis of thioethers, depending on different types of oxime esters. Operational simplicity, mild reaction conditions, and flexible options of leaving group demonstrate the generality and synthetic utility of this approach. Such an approach can also enable an interesting thiol‐catalysis for the synthesis of phenanthridines. [ABSTRACT FROM AUTHOR]

We report a study of solvent effects on the rate, selectivity, and mechanism of (hetero)aryl (pseudo)halide oxidative addition to Pd(PCy3)2 as an exemplar of L2Pd(0) species. First, 2‐chloro‐3‐aminopyridine is observed to undergo faster oxidative addition in toluene compared to more polar solvents, which is not consistent with the trend we observe with many other 2‐halopyridines. We attribute this to solvent basicity hydrogen bonding between solvent and substrate. Greater hydrogen bond donation from the substrate leads to a more electron‐rich aromatic system, and therefore slower oxidative addition. We demonstrate how this affects rate and site‐selectivity for hydrogen bond donating substrates. Second, electron‐deficient multihalogenated pyridines exhibit improved site‐selectivity in polar solvents, which we attribute to different C−X sites undergoing oxidative addition by two different mechanisms. The C−X site that favours the more polar nucleophilic displacement transition state is preferred over the site that favours a less‐polar 3‐centered transition state. Finally, (hetero)aryl triflates consistently undergo faster oxidative addition in more polar solvents, which we attribute to highly polar nucleophilic displacement transition states. This leads to improved site‐selectivity for C−OTf oxidative addition, even in the presence of highly reactive 2‐pyridyl halides. [ABSTRACT FROM AUTHOR]

Quantitative molecular structure‐reactivity models are useful for generating predictions to guide synthesis design, and in formulating and testing mechanistic hypotheses. We report an expanded multivariate linear regression (MLR) model for the rate of (hetero)aryl (pseudo)halide oxidative addition to L2Pd(0), here exemplified by Pd(PCy3)2. This builds on a prior model from our group, with additional substrate classes (aryl chlorides and iodides) and reaction solvents (THF, toluene, THF/DMF mixture). Overall solvent effects across the entire substrate set are minimal under these conditions, enabling a unified MLR model without introduction of new molecular descriptors beyond the original five. Examining the mechanistic origin of the two molecular electrostatic potential (ESP) descriptors led to generation of a simpler, four descriptor model that is suitable for aryl halides, but not for 2‐halopyridines. Using this model we identified a mechanistic outlier, 2‐pyridyl triflate, which undergoes a nucleophilic displacement oxidative addition that does not involve the adjacent nitrogen atom. Finally, we discuss the relationship between C−X bond strength and oxidative addition rates, and compare the intrinsic bond strength index (IBSI) to bond dissociation enthalpy (BDE) as a bond strength descriptor. [ABSTRACT FROM AUTHOR]

A nickel‐catalyzed cross‐coupling reaction has been developed using two distinct electrophiles: an aryl alkyl selenide and an aryl bromide. The organoselenium compound, due to the lower bond dissociation energy of the C−Se bond, acts as a pseudohalide. This one‐pot reaction proceeds by cleaving the C−Se bond, producing the desired biaryls in moderate to good yields. The use of commercially available aryl bromides eliminates the handling of pre‐formed organomagnesium reagents, enhancing the practicality and applicability of this approach. [ABSTRACT FROM AUTHOR]

The synthetic potential of substituted 1,4‐dioxenes is well recognised, although the chemistry of 2‐aryl‐1,4‐dioxenes is relatively unexplored. Their transition metal‐catalysed synthesis has been limited to Stille‐type cross‐coupling chemistry, typically showing long reaction times, or proceeding at high reaction temperatures. Here we present a facile and general methodology for the cross‐coupling of aryl bromides with lithium 1,4‐dioxene, affording a range of 2‐aryl‐1,4‐dioxenes in generally good yields. We highlight the synthetic applicability of this transformation at multigram scale, and demonstrate the versatility of the products by conversion of the dioxene units to various carbonyl‐based functionalities. Additionally, we present a concise two‐step synthesis of an arylated analogue to a known 1,4‐dioxene‐based antifungal agent. [ABSTRACT FROM AUTHOR]

Alkenes are fundamental functional groups which feature in various materials and bioactive molecules; however, efficient divergent strategies for their stereodefined synthesis are difficult. In this regard, numerous synthetic methodologies have been developed to construct carbon–carbon bonds with regio‐ and stereoselectivity, enabling the predictable and efficient synthesis of stereodefined alkenes. In fact, an appealing alternative approach for accessing challenging stereodefined alkene molecular frameworks could involve the sequential selective activation and cross‐coupling of strong bonds instead of conventional C−C bond formation. In this study, we introduce a series of programmed site‐ and stereoselective strategies that capitalizes on the versatile reactivity of readily accessible polymetalloid alkenes (i.e. polyborylated alkenes), through a tandem cross‐coupling reaction, which is catalyzed by an organometallic Rh‐complex to produce complex molecular scaffolds. By merging selective C−B and remote C−H bond functionalization, we achieve the in situ generation of polyfunctional C(sp2)‐nucleophilic intermediates. These species can be further modified by selective coupling reactions with various C‐based electrophiles, enabling the formation of C(sp2)−C(sp3) bond for the generation of even more complex molecular architectures using the readily available starting polyborylated‐alkenes. Mechanistic and computational studies provide insight into the origins of the stereoselectivities and C−H activation via a 1,4‐Rh migration process. [ABSTRACT FROM AUTHOR]

New conjugated 2,6-diphenylaniline-azulene co-oligomers of linear and branched structure were synthesized by the interaction of borylazulenes with diphenylaniline bromides under Suzuki–Miyaura cross-coupling conditions. The obtained diphenylaniline-azulene co-oligomers intensively absorb and emit visible light (410–700 nm region); in particular, they exhibit strong emissions in the green, as well as orange, range, with maxima of 510/590 nm. It is shown that such properties appear as a result of the positive resonance exposure to aniline fragments significantly rearranging the electronic structure of azulene, in particular, the levels and energy gaps of frontal HOMO–LUMO orbitals. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: We herein describe a Cp*RhIII‐catalyzed C(sp3)–H mono‐arylation of 8‐methylquinolines with benign arylsilanes. The use of 1‐adamantane carboxylic acid can benefit the efficiency in this transformation, and AgF was both activator and reoxidant. Control experiments indicated inability of C—H cleavage in determining the rate of the reaction. [ABSTRACT FROM AUTHOR]

The present article presents a personal account on the synthesis of heterocycles by the combination of regioselective Pd-catalyzed cross-coupling reactions of polyhalogenated heterocycles, i.e., Suzuki–Miyaura and Sonogashira reactions, with alkyne-carbonyl-metathesis (ACM) reactions. The products, which show interesting optical, electronic or medicinal properties, are not readily available by other methods. [ABSTRACT FROM AUTHOR]

Herein, for the first time, we disclose the gold‐catalyzed alkoxy‐carbonylation of aryl and vinyl iodides utilizing ligand‐enabled Au(I)/Au(III) redox catalysis. The present methodology is found to be general, efficient, employs mild reaction conditions and showcases a broad substrate scope even with structurally complex molecules. Density functional theory (DFT) calculations revealed mechanistic pathways distinct from those of conventional transition metal‐catalyzed carbonylation reactions. [ABSTRACT FROM AUTHOR]

Comprehensive Summary Conjugate addition and allylic substitution are two essential chemical transformations, and they could be competitive for substrates with multiple reactive sites. Herein, we report the diversified enantioselective synthesis of cyclobutenes via the functionalization of cyclobutenones. The conjugate addition of cyclobutenones with arylzinc halides provided enantioenriched cyclobutenes with all‐carbon quaternary centers. On the other hand, when cyclobutenones with gem‐dichloro groups were employed, a chemo‐ and enantioselective allylic substitution occurred. Further synthetic utility was demonstrated for synthesizing versatile cyclobutane derivatives, together with ring‐opening and expansion products. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The construction of acyclic quaternary carbon stereocenters, which are ubiquitous in many bioactive compounds, pharmaceuticals and natural products, has been a long persuit in synthetic organic chemistry. Among numerous methods, enantioselective nickel‐catalysis has attracted incremental attention in recent years. This review summarizes the recent development in the asymmetric strategies, research progress, mechanistic investigations for the generation of acyclic quaternary carbon stereocenters via enantioselective nickel catalysis. Key Scientists: In 2006, the Zhou group and RajanBabu group realized the nickel‐catalyzed enantioselective hydrovinylation of α‐substituted styrenes and ethylene to construct acyclic quaternary carbon stereocenters (QCSs) by using spiro‐ and binaphthyl phosphoramidite ligands, respectively. In 2016, Watson developed a nickel‐catalyzed Suzuki‐Miyaura arylation to generate acyclic QCSs via chirality transfer reaction. In 2017, the Feng and the Fu group developed nickel‐catalyzed enantioselective conjugated/Michael additions to build acyclic QCSs, respectively. In 2020, the Fang group made the first success in the construction of QCSs by nickel‐catalyzed hydrocyanation of alkenes and allenes. In 2021, Gregory C. Fu and co‐workers disclosed a nickel‐catalyzed enantioselective α‐functionalization of carbonyl compounds that could form acyclic QCSs. At the same time, the Shi group constructed chiral acyclic QCSs via nickel‐catalyzed functionalization of alkenes. In 2023, Kleij and co‐workers applied a new strategy for Ni‐catalyzed regio‐ and enantioselective homoallylic coupling to construct acyclic QCSs. In the same year, Tao and co‐workers demonstrated a novel strategy that is dinickel‐catalyzed enantioselective α‐alkylation of carbonyl compounds with alkyl iodides. [ABSTRACT FROM AUTHOR]

Reliable radical precursors are crucial for photocatalytic processes. In particular, heteroatom‐stabilized radicals have attracted considerable research interest in photocatalysis. Among them, α‐amino radicals have received the most attention, while the research on α‐hydroxy radicals is much less developed. Herein, we present O‐PMP α‐hydroxycarboxylic acids as novel precursors for the formation of oxygen‐stabilized radicals. These radicals have been successfully used as building blocks in Pd‐catalyzed allylation reactions, Ni‐catalyzed arylation and alkenylation reactions, and Giese reactions. A subsequent deprotection step liberates the corresponding hydroxyalkylation products. [ABSTRACT FROM AUTHOR]

A chemo- and regioselective hydroarylation of vinylsilanes with (hetero)aryl iodides under Ni–H catalysis is reported. This mild and straightforward protocol furnishes the anti-Markovnikov products in good yields as single regioisomers. This study demonstrates excellent control over the chemoselectivity and complements existing methods for the construction of homobenzylic silanes. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The construction of acyclic quaternary carbon stereocenters, which are ubiquitous in many bioactive compounds, pharmaceuticals and natural products, has been a long persuit in synthetic organic chemistry. Among numerous methods, enantioselective nickel‐catalysis has attracted incremental attention in recent years. This review summarizes the recent development in the asymmetric strategies, research progress, mechanistic investigations for the generation of acyclic quaternary carbon stereocenters via enantioselective nickel catalysis. Key Scientists: In 2006, the Zhou group and RajanBabu group realized the nickel‐catalyzed enantioselective hydrovinylation of α‐substituted styrenes and ethylene to construct acyclic quaternary carbon stereocenters (QCSs) by using spiro‐ and binaphthyl phosphoramidite ligands, respectively. In 2016, Watson developed a nickel‐catalyzed Suzuki‐Miyaura arylation to generate acyclic QCSs via chirality transfer reaction. In 2017, the Feng and the Fu group developed nickel‐catalyzed enantioselective conjugated/Michael additions to build acyclic QCSs, respectively. In 2020, the Fang group made the first success in the construction of QCSs by nickel‐catalyzed hydrocyanation of alkenes and allenes. In 2021, Gregory C. Fu and co‐workers disclosed a nickel‐catalyzed enantioselective α‐functionalization of carbonyl compounds that could form acyclic QCSs. At the same time, the Shi group constructed chiral acyclic QCSs via nickel‐catalyzed functionalization of alkenes. In 2023, Kleij and co‐workers applied a new strategy for Ni‐catalyzed regio‐ and enantioselective homoallylic coupling to construct acyclic QCSs. In the same year, Tao and co‐workers demonstrated a novel strategy that is dinickel‐catalyzed enantioselective α‐alkylation of carbonyl compounds with alkyl iodides. [ABSTRACT FROM AUTHOR]

This short review article demonstrates recent techniques for the typical conversion of adamantyl C(sp3)−Br bond to various C−C, C−N, and C−X bonds enabled by multiple conditions and reagents with the use of organometallic reagents. This work mainly focuses on developing a mild and convenient system for the selective preparation of substituted adamantyl zinc and magnesium reagents (Ad‐MX) bearing different functional groups on the adamantyl framework. The adamantane scaffolds were selectively functionalized using a various of catalytic methods, most likely organometallic‐Zn, Mg reagent‐mediated Negishi cross‐coupling reactions, acylation, arylation, thiolation, 1,2/1,4‐addition, alkynylation, amination, halogenation, and allylation, etc. Over the years adamantyl derivatives have been broadly studied in various medicinal applications, drug development, supramolecular chemistry, material science, and nanotechnologies, etc. [ABSTRACT FROM AUTHOR]

Photoelectrochemistry (PEC) is burgeoning as an innovative solution to organic synthesis. However, the current PEC systems suffer from limited reaction types and unsatisfactory performances. Herein, we employ efficient BiVO4 photoanodes with tailored deposition layers for customizing two PEC approaches toward C−N and C−P bond formation. Our process proceeds under mild reaction conditions, deploying easily available substrates and ultra‐low potentials. Beyond photocatalysis and electrocatalysis, customized PEC offers high efficiency, good functional group tolerance, and substantial applicability for decorating drug molecules, highlighting its promising potential to enrich the synthetic toolbox for broader organic chemistry of practical applications. [ABSTRACT FROM AUTHOR]

This review introduces the synthetic organic chemical value of α‐bromocarbonyl compounds with tertiary carbons. This α‐bromocarbonyl compound with a tertiary carbon has been used primarily only as a radical initiator in atom transfer radical polymerization (ATRP) reactions. However, with the recent development of photo‐radical reactions (around 2010), research on the use of α‐bromocarbonyl compounds as tertiary alkyl radical precursors became popular (around 2012). As more examples were reported, α‐bromocarbonyl compounds were studied not only as radicals but also for their applications in organometallic and ionic reactions. That is, α‐bromocarbonyl compounds act as nucleophiles as well as electrophiles. The carbonyl group of α‐bromocarbonyl compounds is also attractive because it allows the skeleton to be converted after the reaction, and it is being applied to total synthesis. In our survey until 2022, α‐bromocarbonyl compounds can be used to perform a full range of reactions necessary for organic synthesis, including multi‐component reactions, cross‐coupling, substitution, cyclization, rearrangement, stereospecific reactions, asymmetric reactions. α‐Bromocarbonyl compounds have created a new trend in tertiary alkylation, which until then had limited reaction patterns in organic synthesis. This review focuses on how α‐bromocarbonyl compounds can be used in synthetic organic chemistry. [ABSTRACT FROM AUTHOR]

The development of palladium‐catalyzed fluorination with biaryl monophosphine ligands has faced two important problems that limit its application for bromoarenes: the formation of regioisomers and insufficient catalysis for heteroaryl substrates as bromothiophene derivatives. Overcoming these problems requires more ligand design. In this work, reliable theoretical calculations were used to elucidate important ligand features necessary for achieving more rate acceleration and selectivity. These features include increasing the ligand‐substrate repulsion and creating a negative charge in the space around the fluoride ion bonded to the palladium. The investigated L5 ligand presents these features, and the calculations predict that this ligand completely suppresses the regioisomer formation in the difficult case of 4‐bromoanisole. In addition, the free energy barriers are decreased by 2–3 kcal mol−1 in comparison with the catalysis involving the AlPhos ligand. Thus, the present study points out a direction for new developments in palladium‐catalyzed fluorination. [ABSTRACT FROM AUTHOR]

In the past few decades, transition-metal-catalyzed direct amination of aryl halides with ammonia has attracted significant attention from chemists because of its broad substrate scope, good functional group compatibility, and high reaction selectivity. Herein, recent examples of transition-metal-catalyzed syntheses of aniline derivatives starting from aryl halides are reviewed. 1 Introduction 2 Heat-Driven Transition-Metal-Catalyzed Amination of Aryl Electrophiles 2.1 Palladium-Catalyzed Amination 2.2 Copper-Catalyzed Amination 2.3 Nickel-Catalyzed Amination 3 Light-Driven Transition-Metal-Catalyzed Amination of Aryl Electrophiles 4 Conclusion and Outlook [ABSTRACT FROM AUTHOR]

Here we report, synthesis of ferrocenyl based bis(pyrazolyl) palladium complexes. The catalytic utility of the complexes in the cross‐coupling of triarylbismuthanes and aryl bromides was evaluated. Our ferrocenyl based palladium complex showed wide substrate scope for both triarylbismuthanes and aryl bromides. Further, the current catalytic system also showed superior activity over the well‐established palladium‐phosphine catalytic system using triarylbismuthanes as reagents. [ABSTRACT FROM AUTHOR]

A number of new deoxyvasicinone (2,3‐dihydropyrrolo[2,1‐b]quinazolin‐9(1H)‐one) and mackinazolinone (6,7,8,9‐tetrahydro‐11H‐pyrido[2,1‐b]quinazolin‐11‐one) derivatives with aryl substituents at C7/C8 and at C5 are reported. These compounds are rare representatives of their kind and were prepared in high yields by Suzuki‐Miyaura cross‐coupling reactions between 7‐bromo‐2,3‐dihydro[2,1‐b]quinazoline‐9‐(1H)‐one, 5,7‐dibromo‐2,3‐dihydro[2,1‐b]quinazoline‐9‐(1H)‐one or 8‐bromomackinazolinone and respective arylboronic acids with palladium acetate as the catalyst. The products were characterized spectroscopically and, in addition, by X‐ray crystal structure analyses in six cases. [ABSTRACT FROM AUTHOR]

Gaseous alkanes represent the most abundant carbon‐based chemical feedstocks in our planet. However, the intrinsic inertness of their C−H bonds has rendered the use of these alkanes very difficult for purposes beyond aerobic combustion and energy intensive processes. Thus, clean and energy‐efficient transformations for their use in synthetic organic chemistry are still rare. Here we report a catalytic methodology for the direct cross‐coupling of gaseous alkanes with (hetero)aryl bromides through the combination of metallaphotoredox‐mediated hydrogen atom transfer and nickel catalysis. This protocol provides an efficient platform for the addition of short alkyl groups into diverse (hetero) aromatic rings, providing a wide range of high‐value alkyl(hetero)arenes, and bypassing the longstanding need of using preactivated alkylating agents in C(sp2)‐C(sp3) cross‐couplings. The method features high chemoselectivity, regioselectivity and a remarkable functional group tolerance, operates under mild conditions, and exhibits operational simplicity [ABSTRACT FROM AUTHOR]

Non‐directed regioselective activation of bis(boronic esters), followed by functionalization, is reported. A bulky activator is shown to selectively activate the less hindered boronic ester enabling it to undergo stereospecific cross‐coupling to a variety of electrophiles. This steric‐based regioselectivity provides a simple and efficient method to prepare highly functionalized, enantiomerically enriched products starting from simple alkenes. [ABSTRACT FROM AUTHOR]

While iron‐catalyzed C(sp2)−C(sp3) cross‐couplings have been widely studied and developed in the last decade, alkyl‐alkyl cross‐coupling systems with iron remain underdeveloped despite the importance of C(sp3)−C(sp3) bonds in organic synthesis. A major challenge to the development of these reactions is the current lack of fundamental insight into ligand effects and organoiron intermediates that enable effective alkyl‐alkyl couplings. The current study addresses this longstanding limitation using a combination of 57Fe Mössbauer spectroscopy, SC‐XRD (single‐crystal X‐ray diffraction) and reactivity studies of alkyl‐alkyl coupling with iron‐Xantphos to define the in situ formed iron‐Xantphos intermediates in catalysis. Combined with detailed reactivity studies, the nature of the key mechanistic pathways in catalysis and ligands effects to achieve effective alkyl‐alkyl cross‐coupling over competing β‐H elimination pathways are probed. Overall, these foundational studies provide a platform for future bespoke ligand and pre‐catalyst design for alkyl‐alkyl cross‐coupling methods development with sustainable iron catalysis. [ABSTRACT FROM AUTHOR]

Electro‐organic synthesis, a method that uses electrical current to drive various organic transformations, has garnered significant attention, and so has heterogeneous electrosynthesis, a process that produces chemicals through electrochemical reactions at the interface between the electrode and an electrolyte. This concept highlights the synergistic potential of heterogeneous electrocatalysts, particularly in their use in cross‐coupling reactions. After thoroughly analyzing existing literature, key examples have been highlighted in this paper where heterogeneous electrocatalysts have facilitated the transformation of simple starting materials into useful products. This process lowers energy consumption and reduces waste. We hope this short review sparks the interest among those involved in organic electrosynthesis to explore and use heterogeneous electrocatalysis for cross‐coupling reactions. [ABSTRACT FROM AUTHOR]

Organoboron compounds are widely utilized in organic synthesis for their diverse reactivity, modular preparation, and stability compared to other classes of organometallic reagents. While organoboron species are commonly employed as nucleophiles in cross‐coupling reactions, their potential as racemic building blocks in enantioconvergent transformations remains largely untapped. Herein, we demonstrate the direct utilization of alkylboronic pinacol esters in intermolecular enantioconvergent transformations. Specifically, this work describes the development and mechanistic study of an enantioconvergent deborylative cyanation enabled by Cu catalysis. This method imparts a high degree of enantioselectivity and tolerates a wide range of common functional groups and heterocycles. The reaction is proposed to proceed through a radical‐relay mechanism. Aniline‐assisted homolysis of the carbon–boron bond results in prochiral alkyl radicals that are functionalized by in situ generated Cu(II)(CN)2 species in an enantioselective fashion. The Cu(II)(CN)2 intermediate was characterized by electron paramagnetic resonance (EPR) spectroscopy, and its electronic structure was probed using density functional theory (DFT) calculations. Computational studies were carried out to corroborate the proposed radical‐relay mechanism. [ABSTRACT FROM AUTHOR]

Stereospecific approaches allow the introduction of a stereogenic center into complex organic molecules using optically active reagents. Among these, the Pd-catalyzed stereospecific cross-coupling of chiral alkylboron compounds stands out as a highly effective tool for organic synthesis. In parallel with advances in the development of borylation technology, the strategy has recently witnessed a growth in its applicability. This account aims to review the progress on Pd-catalyzed stereospecific B -alkyl Suzuki–Miyaura cross-coupling, tracing its evolution from early breakthroughs to the most recent advances. 1 Introduction 2 Cross-Coupling of 1° Alkylboron Compounds 3 Cross-Coupling of Benzylboron Compounds 4 Cross-Coupling of Allyl- and Propargylboron Compounds 5 Cross-Coupling of Other Types of Activated 2° Alkylboron Compounds 6 Cross-Coupling of Unactivated 2° Alkylboron Compounds 7 Conclusion and Outlook [ABSTRACT FROM AUTHOR]

The purpose of this paper is to propose a new sound source identification method to identify and separate the sound sources generated by the cross-coupled vibration sources inside the cylindrical shell structure. Near-field acoustic holography (NAH) has fundamentally changed sound source identification in that it has enabled the identification of sound sources and the visualization of the 3-D sound field. Nevertheless, the NAH technique is still unable to identify the vibration sources inside a structure and also finds it difficult to identify the contribution of a single sound source to sound fields due to cross-coupling among the vibration sources. To overcome these limitations, a modified operational transfer path analysis (OPA) technique has also been proposed, which can address the cross-coupling between vibration sources. In practice, however, a single identification method often appears to be inadequate. Thus, in this paper, a novel method of merging the NAH technique and the modified OPA technique has been adopted and used to identify the structure-borne sound source of a cylindrical shell. Finally, the adaptability of the proposed method has been demonstrated by numerical simulations and experimentally and it has been shown that the novel method can not only compute the sound field distribution of a cylindrical surface, but also reconstruct other 3-D field distributions, and moreover, can locate a sound source and predict the sound field. [ABSTRACT FROM AUTHOR]

The synchronization control of its dual hydraulic cylinder moving beam in fatigue testing machine requires robustness and high synchronization accuracy. The synchronization control accuracy is affected by the time-varying nonlinearity of parameters, mutual coupling and load disturbance of the multi-cylinder system affect. A novel control strategy with single-cylinder self-immunity and double-cylinder fuzzy single neuron is proposed to overcome the slow compensation response and poor robustness of dynamic adjustability. First the working principle of the moving beam synchronization system of the fatigue testing machine is described, then the mathematical simulation model of the asymmetric single and double cylinders and their synchronization control system are established to carry out the simulation analysis of the tracking performance and synchronization performance. Finally the experimental is setup to verify the simulation analysis. The results show that the designed synchronization controller can meet the application requirements of the fatigue testing machine moving beam extremely well. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Over the past few decades, N‐sulfonyl hydrazones have been recognized as alternative precursors for hazardous diazo compounds in organic synthesis, allowing for diverse innovative and original chemical transformations that were otherwise difficult to achieve. This critical review summarizes the major advancements in the carbene chemistry of N‐sulfonyl hydrazones. The contents of this review are organized based on research conducted by leading scientists who have made significant contributions to this field. The individual carbene transfer reactions and their mechanisms, as well as the potential applications in the synthesis of natural products and complex bioactive molecules, are thoroughly discussed. [ABSTRACT FROM AUTHOR]

A new MOF (Co‐TIST) was synthesized from 2,4,6‐tris (imidazol‐1‐yl)‐1,3,5‐s‐triazine (TIST) and cobalt nitrate. TIST was prepared from the reaction of cyanuric chloride and imidazole and used as a ligand for the formation of MOF. After characterization of Co‐TIST by different methods, we have investigated the carbonyl‐Heck cross‐coupling reaction of aldehydes with aryl halides in the presence of Co‐TIST as a new heterogeneous catalyst. Various ketones were obtained in good to high yields by this method. The reactions did not require high temperature, additives, or large amounts of the catalyst. The catalyst was recycled in five consecutive runs with unimportant decrease in its catalytic activity. Notably, this is the first report of using a MOF for the carbonyl‐Heck cross‐coupling reaction of aryl halides and aldehydes. [ABSTRACT FROM AUTHOR]

This paper presents a tunable center frequency and small size cavity bandpass filter design method. In this method, a capacitor-loaded open terminal coaxial resonator is employed to reduce the size of cavity filters. The resonator is designed and fabricated separately into two parts to achieve the flexible operating frequency purpose. The first part is called the base of the resonator which is simply a pillar and directly fabricated integrally with the cavity housing. The second part called the hat of the resonator is the main part causing the load capacitance in cavity filters. By using different heights of the base part or/and different shapes and sizes of the hat, the operating frequency of cavity filters can be changed flexibly. This method not only reduces the difficulty and cost of cavity filter processing but also makes cavity filters reconfigurable. To demonstrate the effectiveness of the method, a cavity filter sample with a center frequency of 3.45 GHz and a bandwidth of 80 MHz was designed, fabricated, and measured. The measured results show that the insertion loss was smaller than 1.33 dB in the whole bandwidth, one zero-point at 3.350 GHz reaching -68 dB, the rejection at 3.550 GHz was -41 dB, unloaded Q was 5,898, and the dimension of the filter was 128 mm×86 mm×23 mm. [ABSTRACT FROM AUTHOR]

An efficient access to novel families of cyano‐containing polyheteroaromatic D−A molecules with extended π‐conjugation, including dibenzo[c,h][1,6]naphthyridine derivatives, has been elaborated. The synthetic strategy is based on the sequence of metal‐catalyzed annulation and cross‐coupling reactions starting from available 4‐ethynyl‐5,6‐difluoro‐7‐(p‐methoxyphenyl)‐2,1,3‐benzothiadiazole to get a new series of isoquinoline‐linked BTD‐based D−A compounds, which further undergo a selective cyanation to afford the corresponding mono‐CN‐ or di‐CN‐BTD derivatives depending on the reaction conditions. In course of the investigation of cyanation process, a new type of intramolecular heterocyclization included the transformation of the benzothiadiazole core into hardly accessible dibenzo[c,h][1,6]naphthyridine framework has been unexpectedly discovered. The protocols developed tolerate a wide range of donor blocks such as diphenylamine, carbazole, dibenzoazepine and dihydroacridine. [ABSTRACT FROM AUTHOR]

The present review covers various advances in the field of metal‐catalyzed coupling of N‐tosylhydrazones with compounds containing C−H/heteroatom‐H bonds, including transition metal catalysts i. e. Pd, Rh, Cu, Ag, Ni and Co and resulting alkylated, alkenylated, alkynylated, allenylated, annulated and many other products. A metal carbene migratory insertion process play a key role in carbon‐carbon single bond (C−C) and carbon‐carbon double bond (C=C) formation and undergoes variety of cascade reactions to synthesize a wide scope of pharmaceutically and medicinally valuable scaffoldings. [ABSTRACT FROM AUTHOR]

Described herein is a tandem reaction involving a copper chloride‐catalyzed cross‐coupling and an allene‐mediated cyclization of substituted ethynylimidazo[2,1‐b]thiazoles with aromatic N‐tosylhydrazones, producing naphtho[1′,2′4,5]imidazo [2,1‐b]thiazoles in very good yields. This protocol offers the advantages of one‐pot conversion from stable and readily available substrates as well as good functional group compatibility to prepare polycyclic N‐fused heteroaromatic systems. Moreover, the new compounds exhibited promising antitubercular activity. [ABSTRACT FROM AUTHOR]

We report the synthesis of polycyclic uracil derivatives. The method is based on palladium-catalysed Sonogashira–Hagihara and Suzuki–Miyaura cross-coupling reactions followed by Brønsted acid-mediated cycloisomerisation. The developed methodology tolerates various functional groups and leads to moderate up to quantitative yields of the final products. The impact of different functional groups on the optical properties was studied by UV–vis and fluorescence spectroscopy.

Comprehensive Summary: Cross‐electrophile couplings (XEC), a crucial subset of cross‐coupling reactions, center on the formation of robust C—C bonds through the union of two electrophiles. Usually, such reactions have primarily been catalyzed by transition metals. However, with the steady advancements in photochemical and electrochemical technologies, XEC reactions have significantly progressed and broadened their scope, allowing for the utilization of a wider array of tolerable functional groups, thus revealing vast application prospects. This review aims to systematically summarize the current prevalent types of electrophiles and delve into their specific application examples within XEC reactions involving electrophiles with identical functional groups. Specifically, XECs between the same type of halides have received considerable attention, whereas carboxylic acids and alcohols are still in the early stages of investigation. Furthermore, certain other common electrophiles remain unexplored in this context. Moreover, this review underscores the remarkable contributions of photochemistry and electrochemistry in the field of XEC reactions, aiming to provide valuable insights and inspiration for researchers. Also, this review hopes to spark further interest in XEC reactions, thereby fueling the continuous development and advancement of this exciting area of research. Key Scientists: Since the 1960s, advancements in the XEC reaction have been substantial, driven primarily by the application of transition metal catalysts. In this area, many distinguished scientists have contributed their wisdom and efforts. Particularly noteworthy is that, during the systematic study of XEC reactions with the identical functional groups, in 2016, MacMillan achieved a photocatalytic XEC reaction between aryl bromides and alkyl bromides; in 2020, Weix successfully realized a nickel‐catalyzed XEC reaction between aryl chlorides and alkyl chlorides. Concurrently, contributions from researchers such as Mei, Wolf, Sevov, Lin, Shen, Browne, Zhang, and Qiu have expanded the scope of XEC reactions to various halides. By 2022, MacMillan and Baran achieved a significant milestone in the XEC between carboxylic acids, further broadening the scope of research in this area. Also, advancements in the XEC of alcohols have been noted, with researchers including Weix, Lian, Tu, and Stahl conducting pioneering work and successfully executing the XEC of protective groups. It is foreseen that the ongoing research endeavors will primarily concentrate on the expansion of diverse electrophiles. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Organoborons are commonly used building blocks for rapidly increasing molecular complexity. Although significant progress has been made in the selective functionalization of mono‐organoborons, the site‐selective functionalization of poly(organoborons) has attracted substantial interest in organic synthesis, pharmaceuticals, and agrochemicals due to the presence of multiple potential reaction sites. This review discusses various activation modes of the target C–B bond, with diverse transformations being achieved in both a selective and efficient manner. Recent advances in the catalytic selective transformations of 1,n‐diboronates through ionic and radical pathways are highlighted. Furthermore, we summarize the existing challenges and future research directions in this field. Key Scientists: In 1993, Suzuki, Miyaura and coworkers developed a pioneering example of selective arylation towards cis‐1,2‐bis(boryl) alkenes, marking the inception of this field. The Morken group has made significant contributions to the asymmetric diboration of alkenes and realized elegant catalytic functionalization of these compounds since 2004. In 2016, Fernández and colleagues achieved the selective arylation of the internal C–B bond of tri(boronates). Since 2019, the Aggarwal group has developed efficient Giese‐type addition and selective arylation at the more substituted C–B bond of 1,2‐bis(boronic) esters through photoredox catalysis. The controllable regiodivergent alkynylation of 1,3‐bis(boronic) esters was developed by Gao and coworkers in 2023. Recently, Qin conducted elegant research on the programmable late‐stage functionalization of bridge‐substituted bicyclo[1.1.1]pentane (BCP) bis‐boronates. Since 2013, catalytic stereoselective transformations have been developed by several groups, including those led by Morken and Chen. This review summarizes the latest and most significant developments in this field since 1993. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Organoborons are commonly used building blocks for rapidly increasing molecular complexity. Although significant progress has been made in the selective functionalization of mono‐organoborons, the site‐selective functionalization of poly(organoborons) has attracted substantial interest in organic synthesis, pharmaceuticals, and agrochemicals due to the presence of multiple potential reaction sites. This review discusses various activation modes of the target C–B bond, with diverse transformations being achieved in both a selective and efficient manner. Recent advances in the catalytic selective transformations of 1,n‐diboronates through ionic and radical pathways are highlighted. Furthermore, we summarize the existing challenges and future research directions in this field. Key Scientists: In 1993, Suzuki, Miyaura and coworkers developed a pioneering example of selective arylation towards cis‐1,2‐bis(boryl) alkenes, marking the inception of this field. The Morken group has made significant contributions to the asymmetric diboration of alkenes and realized elegant catalytic functionalization of these compounds since 2004. In 2016, Fernández and colleagues achieved the selective arylation of the internal C–B bond of tri(boronates). Since 2019, the Aggarwal group has developed efficient Giese‐type addition and selective arylation at the more substituted C–B bond of 1,2‐bis(boronic) esters through photoredox catalysis. The controllable regiodivergent alkynylation of 1,3‐bis(boronic) esters was developed by Gao and coworkers in 2023. Recently, Qin conducted elegant research on the programmable late‐stage functionalization of bridge‐substituted bicyclo[1.1.1]pentane (BCP) bis‐boronates. Since 2013, catalytic stereoselective transformations have been developed by several groups, including those led by Morken and Chen. This review summarizes the latest and most significant developments in this field since 1993. [ABSTRACT FROM AUTHOR]

A new nickel-catalyzed electrochemical, reductive cross-coupling for the trideuteromethylation of alkyl and aryl bromides is reported in which CD3 arenesulfonate derivatives were used as effective and readily available CD3 sources. The CD3-labeled products were obtained with good yields. It was demonstrated that this methodology is scalable and can be efficiently used for various methylations, including13 CH3 and13 CD3 labeling. [ABSTRACT FROM AUTHOR]

Palladium- and nickel-catalyzed cross-couplings are powerful methods for constructing C–C and C–N bonds, particularly through Suzuki–Miyaura and Buchwald–Hartwig reactions. Although aryl iodides, bromides, and triflates are the most commonly used substrates, aryl chlorides are less frequently utilized due to their lower reactivity. However, they are appealing because they are readily available and inexpensive. This short review highlights recent developments on the Suzuki–Miyaura and Buchwald–Hartwig cross-couplings of aryl chlorides, using both homogeneous and heterogeneous catalysis with palladium and nickel. 1 Introduction 2 Suzuki–Miyaura Cross-Couplings 2.1 Homogeneous Palladium Catalysis 2.2 Heterogeneous Palladium Catalysis 2.3 Homogeneous Nickel Catalysis 2.4 Heterogeneous Nickel Catalysis 3 Buchwald–Hartwig Amination Reactions 3.1 Homogeneous Palladium Catalysis 3.2 Heterogeneous Palladium Catalysis 3.3 Homogeneous Nickel Catalysis 3.4 Heterogeneous Nickel Catalysis 4 Conclusion [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Recent advances in transition metal‐catalyzed o‐carborane B—H activation have led to the rapid development of various methodologies for cage boron functionalization. For catalytic cage B—H acyloxylation, intermolecular oxygenation gave products with different regioselectivities (B(3)‐, B(4)‐, and B(8,9)‐selectivities). Herein, an efficient palladium‐catalyzed direct cage B(4)–H oxygenation of o‐carboranylacetic acids has been achieved, where the carboxylic group serves as not only a directing group, but also a coupling partner. A wide range of substituted o‐carboranylacetic acids have been cyclized via the formation of B(4)−O bond to give the corresponding γ‐lactones in modest to excellent yields. A Pd(IV) intermediate is proposed to be involved in the catalytic cycle. This work offers valuable references for the BH/OH dehydrocoupling reactions under mild conditions to produce carborane‐featuring functional molecules. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: α‐Azaarene quaternary carbon centers are prevalent in drug molecules, making the development of efficient synthetic approaches of great interest. Herein, we describe an unprecedented method for constructing α‐all‐carbon quaternary carbon‐centered azaarenes by employing photocatalytic reductive coupling of various 2,2‐disubstituted cycloproarylketones with readily available cyanoazaarenes. The reaction proceeds with high efficiency, displaying excellent compatibility with various functional groups and demonstrating high chemo‐ and regioselectivity. Mechanistic investigations suggest that consecutive photo‐induced electron transfer (ConPET) plays a crucial role in the formation of photocatalyst with greater reducing capability, ultimately enabling the direct reductive conversion of unreactive π‐bonds under mild and transition‐metal‐free conditions. [ABSTRACT FROM AUTHOR]